The present invention generally relates to disc recording and/or reproducing apparatuses, and more particularly to a magnetic disc recording and/or reproducing apparatus in which a first recording/reproducing unit having a recording and reproducing head and a disc driving mechanism for recording and/or reproducing information signals on and/or from a first magnetic disc having a first diameter and a second recording/reproducing unit similarly designed but adapted for a second magnetic disc having a second diameter are selectively used depending on which one of the first and second magnetic discs is to be played.
Generally, electronic information processing systems such as personal computers, word processors and the like use a magnetic disc recording and/or reproducing apparatus as an external memory device. In such a magnetic disc recording and/or reproducing apparatus, information signals are magnetically recorded and reproduced on and from a magnetic disc.
Currently, there exist magnetic discs having standardized diameters such as 3.5 inches, 5.25 inches, 8 inches and the like. Various magnetic disc recording and/or reproducing apparatuses are designed for respective sizes of the magnetic discs. Usually, an electronic information processing system uses only one type of the magnetic disc recording and/or reproducing apparatus which is designed exclusively for playing a particular magnetic disc having a particular diameter. Thus, only one type of the magnetic disc can be used in an electronic information processing system.
For example, an electronic information processing system incorporating a magnetic disc recording and/or reproducing apparatus designed for a magnetic disc having a diameter of 5.25 inches cannot use a smaller magnetic disc having a diameter of 3.5 inches nor a larger magnetic disc having a diameter of 8 inches. Thus, there is a problem in that the electronic information processing system cannot use information and software recorded on a magnetic disc having a diameter of 3.5 inches or 8 inches. A similar problem arises when a software frequently used in the information processing system is recorded on a magnetic disc having a diameter of 3.5 inches or 8 inches and the software cannot be copied on a magnetic disc having a diameter of 5.25 inches.